Touch detection circuit, touch detection method, and electronic apparatus

ABSTRACT

A touch detection circuit includes: a map generation section configured to compare a touch signal corresponding to a proximity state of an external proximity object with each of a plurality of thresholds to generate a plurality of pieces of map data each showing touch regions; a labeling section configured to selectively perform labeling on the touch regions in the plurality of pieces of map data, based on inclusive relationship of the touch regions between the plurality of pieces of map data; and a detection section configured to perform touch detection based on processing results by the labeling section.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Priority PatentApplication JP 2013-162925 filed in the Japan Patent Office on Aug. 6,2013, the entire content of which is hereby incorporated by reference.

BACKGROUND

The present disclosure relates to a touch detection circuit and a touchdetection method that are used in a touch panel detecting an object thatis in contact with or in proximity to the touch panel, and to anelectronic apparatus provided with such a touch detection circuit.

In recent years, a touch panel is mounted on various electronicapparatuses such as mobile information terminals including smartphones,portable game machines, and personal computers. In such electronicapparatuses, since a keyboard, buttons, and the like used so far becomeunnecessary, it is possible to downsize the apparatuses. In addition,various distinctive user interfaces unique for the touch panel have beendeveloped, which allows users to perform information input and operationmore intuitively. Accordingly, importance of the touch panel as a userinterface is further increased.

In such a touch panel, a touch detection signal corresponding to aproximity state of an object (an external proximity object) that is incontact with or is in proximity to the touch panel and a predeterminedthreshold are compared to determine a region (a touch region) wheretouch event is performed. For example, in Japanese Unexamined PatentApplication Publication No. 2012-69066, a touch detection device thatcompares a detection intensity value according to the external proximityobject with a plurality of predetermined thresholds is disclosed.

SUMMARY

Incidentally, at the time of operating an electronic apparatus with useof a touch panel, there are a case where one user performs operationwith use of a plurality of fingers and a case where a plurality of usersperforms operation. In such a case, it is necessary for the touch panelto detect a plurality of touch events (multi-touch). Additional featuresand advantages are described herein, and will be apparent from thefollowing Detailed Description and the figures.

It is desirable to provide a touch detection circuit, a touch detectionmethod, and an electronic apparatus that are capable of detecting aplurality of touch events.

According to an embodiment of the disclosure, there is provided a touchdetection circuit including: a map generation section configured tocompare a touch signal corresponding to a proximity state of an externalproximity object with each of a plurality of thresholds to generate aplurality of pieces of map data each showing touch regions; a labelingsection configured to selectively perform labeling on the touch regionsin the plurality of pieces of map data, based on inclusive relationshipof the touch regions between the plurality of pieces of map data; and adetection section configured to perform touch detection based onprocessing results by the labeling section.

According to an embodiment of the disclosure, there is provided a touchdetection method including: comparing a touch signal corresponding to aproximity state of an external proximity object with each of a pluralityof thresholds to generate a plurality of pieces of map data each showingtouch regions; selectively performing labeling on the touch regions inthe plurality of pieces of map data based on inclusive relationship ofthe touch regions between the plurality of pieces of map data; andperforming touch detection based on labeling results.

According to an embodiment of the disclosure, there is provided anelectronic apparatus provided with a touch detection device configuredto detect an external proximity object, and a touch detection circuit.The touch detection circuit includes: a map generation sectionconfigured to compare a touch signal corresponding to a proximity stateof the external proximity object to the touch detection device with eachof a plurality of thresholds to generate a plurality of pieces of mapdata each showing touch regions; a labeling section configured toselectively perform labeling on the touch regions in the plurality ofpieces of map data, based on inclusive relationship of the touch regionsbetween the plurality of pieces of map data; and a detection sectionconfigured to perform touch detection based on processing results by thelabeling section.

In the touch detection circuit, the touch detection method, and theelectronic apparatus according to the respective embodiments of thedisclosure, the touch signal and the plurality of thresholds arecompared to generate the plurality of pieces of map data, and the touchregions in the plurality of pieces of map data are labeled. At thistime, the touch regions are selectively subject to labeling based on theinclusive relationship of the touch regions between the plurality ofpieces of map data.

According to the touch detection circuit, the touch detection method,and the electronic apparatus according to the respective embodiments ofthe disclosure, the labeling is selectively performed based on theinclusive relationship of the touch regions between the plurality ofpieces of map data. Therefore, it is possible to detect the plurality oftouch events.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the technology as claimed.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments and,together with the specification, serve to explain the principles of thetechnology.

FIG. 1 is a block diagram illustrating a configuration example of atouch panel according to a first embodiment of the disclosure.

FIG. 2 is a perspective view illustrating a configuration example of atouch detection device illustrated in FIG. 1.

FIG. 3 is a timing waveform chart illustrating an operation example ofthe touch detection device and an analog signal processing sectionillustrated in FIG. 1.

FIG. 4 is a block diagram illustrating a configuration example of atouch position detection section illustrated in FIG. 1.

FIG. 5 is an explanatory diagram illustrating an operation example of athreshold setting section and a binarizing section illustrated in FIG.4.

FIG. 6 is an explanatory diagram illustrating a mounting example of thetouch panel illustrated in FIG. 1.

FIG. 7A is an explanatory diagram illustrating an example of map dataand label information.

FIG. 7B is another explanatory diagram illustrating an example of themap data and the label information.

FIG. 7C is another explanatory diagram illustrating an example of themap data and the label information.

FIG. 7D is another explanatory diagram illustrating an example of themap data and the label information.

FIG. 8 is an explanatory diagram illustrating inclusive relationship oftouch regions.

FIG. 9 is a flowchart illustrating an operation example of a touchregion arithmetic section illustrated in FIG. 4.

FIG. 10 is an explanatory diagram illustrating an operation example ofthe touch region arithmetic section illustrated in FIG. 4.

FIG. 11 is another explanatory diagram illustrating an operation exampleof the touch region arithmetic section illustrated in FIG. 4.

FIG. 12 is another explanatory diagram illustrating an operation exampleof the touch region arithmetic section illustrated in FIG. 4.

FIG. 13 illustrates the map data MAPA to MAPD and the label informationLA and LB according to an embodiment.

FIG. 14 is an explanatory diagram illustrating an operation example of atouch coordinate calculation section illustrated in FIG. 4.

FIG. 15 is an explanatory diagram illustrating an operation example of atouch panel according to a comparative example.

FIG. 16 is a flowchart illustrating an operation example of a touchregion arithmetic section according to a second embodiment.

FIG. 17A is an explanatory diagram illustrating an operation example ofthe touch region arithmetic section according to the second embodiment.

FIG. 17B is another explanatory diagram illustrating an operationexample of the touch region arithmetic section according to the secondembodiment.

FIG. 17C is another explanatory diagram illustrating an operationexample of the touch region arithmetic section according to the secondembodiment.

FIG. 17D is another explanatory diagram illustrating an operationexample of the touch region arithmetic section according to the secondembodiment.

FIG. 17E is another explanatory diagram illustrating an operationexample of the touch region arithmetic section according to the secondembodiment.

FIG. 18 is a block diagram illustrating an operation example of a touchposition detection section according to a third embodiment.

FIG. 19 is a flowchart illustrating an operation example of a labelingprocessing section illustrated in FIG. 18.

FIG. 20 is another flowchart illustrating an operation example of thelabeling processing section illustrated in FIG. 18.

FIG. 21A is an explanatory diagram illustrating an operation example ofthe labeling processing section illustrated in FIG. 18.

FIG. 21B is another explanatory diagram illustrating an operationexample of the labeling processing section illustrated in FIG. 18.

FIG. 21C is another explanatory diagram illustrating an operationexample of the labeling processing section illustrated in FIG. 18.

FIG. 21D is another explanatory diagram illustrating an operationexample of the labeling processing section illustrated in FIG. 18.

FIG. 21E is another explanatory diagram illustrating an operationexample of the labeling processing section illustrated in FIG. 18.

FIG. 22 is a perspective view illustrating an appearance configurationof a smartphone to which any of the embodiments is applied.

FIG. 23 is a perspective view illustrating an appearance configurationof a portable game machine to which any of the embodiments is applied.

FIG. 24 is a perspective view illustrating an appearance configurationof a notebook personal computer to which any of the embodiments isapplied.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the disclosure will be describedin detail with reference to drawings. Note that description will begiven in the following order.

1. First embodiment

2. Second embodiment

3. Third embodiment

4. Application examples

1. First Embodiment Configuration Example

FIG. 1 illustrates a configuration example of a touch panel according toa first embodiment. A touch panel 1 is an electrostatic capacitance typetouch panel. Note that a touch detection circuit and a touch detectionmethod according to respective embodiments of the disclosure areembodied by the present embodiment, and thus are described together. Thetouch panel 1 includes a touch detection device 10, an analog signalprocessing section 20, and a digital signal processing section 30.

The touch detection device 10 may detect an object (an externalproximity object) that is in contact with or in proximity to a touchdetection surface, for example, a finger of a user or the like. Thetouch detection device 10 includes a plurality of drive electrodes 11, aplurality of sensor electrodes 12, and a drive section 13.

The plurality of drive electrodes 11 is each an electrode having a stripshape, and is provided side by side in a direction intersecting anextending direction thereof. One end of each of the drive electrodes 11is connected to the drive section 13, and is supplied with a drivesignal DRV.

The plurality of sensor electrodes 12 is each an electrode that extendsin a direction intersecting the extending direction of the plurality ofdrive electrodes 11, and is provided side by side in a directionintersecting an extending direction thereof. Electrostatic capacitancesare formed at parts where the plurality of drive electrodes 11 and theplurality of sensor electrodes 12 intersect. One end of each of thesensor electrodes 12 is connected to the analog signal processingsection 20.

The drive section 13 sequentially applies the drive signal DRV to theplurality of drive electrodes 11 based on a control signal (a digitalsignal) supplied from the analog signal processing section 20.

FIG. 2 is a perspective view illustrating a configuration example of thetouch detection device 10. In this example, the drive electrodes 11 areprovided so as to extend in a lateral direction of the figure, and thesensor electrodes 12 are provided so as to extend in a depth directionof the figure. The drive electrodes 11 and the sensor electrodes 12 areformed in different layers separately from each other. Therefore, theelectrostatic capacitances are formed at the parts where the pluralityof drive electrodes 11 intersects the plurality of sensor electrodes 12.

Each of the drive electrodes 11 is sequentially supplied with the drivesignal DRV by the drive section 13, and is subjected to scan driving.The drive signal DRV is transmitted to the sensor electrodes 12 throughthe electrostatic capacitances between the drive electrodes 11 and thesensor electrodes 12. At this time, a signal (a detection signal SDET)appearing in each of the sensor electrodes 12 corresponds to a proximitystate of the external proximity object. In other words, when theexternal proximity object is present, an electrostatic capacitance isgenerated between the sensor electrodes 12 and the external proximityobject, in addition to the electrostatic capacitances between the driveelectrodes 11 and the sensor electrodes 12. Therefore, the detectionsignals SDET change based on the proximity state of the externalproximity object. The analog signal processing section 20 and thedigital signal processing section 30 detect the external proximityobject based on such detection signals SDET.

In this way, in the touch detection device 10, the parts where theplurality of drive electrodes 11 intersects the plurality of sensorelectrodes 12 each function as an electrostatic capacitance type touchsensor. In the touch detection device 10, such touch sensors arearranged in a matrix. Therefore, scanning is performed over the entiretouch detection surface of the touch detection device 10, which makes itpossible to detect a position (a coordinate) where contact or proximityof the external proximity object occurs.

The analog signal processing section 20 generates map data MAP1 thatindicates a detection result by all of the touch sensors of the touchdetection device 10, based on the detection signals SDET supplied fromthe plurality of sensor electrodes 12 of the touch detection device 10.The analog signal processing section 20 includes a multiplexer 21, anoperational amplifier 22, a capacitor 23, a switch 24, a sample and hold(S/H) circuit 25, an analog to digital converter (ADC) 26, and a controlsection 27.

The multiplexer 21 sequentially selects and outputs one of the detectedsignals SDET supplied from the plurality of sensor electrodes 12 of thetouch detection device 10, based on the control signal supplied from thecontrol section 27. Note that this is not limitative, and alternatively,for example, the multiplexer 21 is not provided and circuits such asoperational amplifiers 22 as many as the plurality of sensor electrodes12 of the touch detection device 10 may be provided, and parallelprocessing may be performed.

The operational amplifier 22 amplifies and outputs a differentialvoltage between a voltage at a positive input terminal and a voltage ofa negative input terminal. The positive input terminal is grounded inthis example. The negative input terminal is connected to an outputterminal of the multiplexer 21 and to a first end of the capacitor 23and a first end of the switch 24. An output terminal of the operationalamplifier 22 is connected to a second end of the capacitor 23 and asecond end of the switch 24. The first end of the capacitor 23 isconnected to the negative input terminal of the operational amplifier22, and the second end thereof is connected to the output terminal ofthe operational amplifier 22. The switch 24 is turned on or off based ona control signal SSW supplied from the control section 27. The first endof the switch 24 is connected to the negative input terminal of theoperational amplifier 22, and the second end thereof is connected to theoutput terminal of the operational amplifier 22.

With this configuration, during a period in which the switch 24 is putinto OFF state, the operational amplifier 22 and the capacitor 23integrate the detection signals SDET supplied from the touch detectiondevice 10 and outputs the integrated value as a signal V1. Then, whenthe switch 24 is put into ON state, both ends of the capacitor 23 areelectrically connected to each other, and the integrated value (theoutput signal of the operational amplifier 22) is reset.

The S/H circuit 25 samples the output signal V1 of the operationalamplifier 22 based on the control signal supplied from the controlsection 27, and holds the sampling results for a certain period of time.

The ADC 26 converts an output signal that is an analog signal, of theS/H circuit 25 into a digital code based on the control signal suppliedfrom the control section 27.

The control section 27 supplies control signals to each of the drivesection 13 of the touch detection device 10, the multiplexer 21, theswitch 24, the S/H circuit 25, and the ADC 26 to control these circuitsto operate in cooperation with one another.

FIG. 3 illustrates an operation example of the touch detection device 10and the analog signal processing section 20, where (A) illustrates awaveform of the drive signal DRV, (B) illustrates a waveform of thecontrol signal SSW, and (C) illustrates a waveform of the signal V1. Inthis example, the switch 24 is turned on when the control signal SSW isat a high level, and is turned off when the control signal SSW is at alow level. In addition, in (C) of FIG. 3, a solid line indicates awaveform in the case where the external proximity object is present, anda dashed line indicates a waveform in the case where the externalproximity object is not present.

First, at a timing t1, the drive section 13 performs transition of avoltage of the drive signal DRV to be applied to a certain driveelectrode 11 of the plurality of drive electrodes 11, from low level tohigh level ((A) of FIG. 3). The drive signal DRV is transmitted to thesensor electrodes 12 through the electrostatic capacitances between thedrive electrodes 11 and the sensor electrodes 12, and then is output asthe detection signals SDET from the touch detection device 10. Then, theoperational amplifier 22 and the capacitor 23 integrate the detectionsignals SDET, and thus the output signal V1 is decreased to a voltagecorresponding to the proximity state of the external proximity object((C) of FIG. 3).

Then, at a timing t2, the S/H circuit 25 samples the signal V1, and theADC 26 converts the output signal of the S/H circuit 25 into a digitalcode ((C) of FIG. 3).

Next, at a timing t3, the control section 27 changes a voltage of thecontrol signal SSW from low level to high level ((B) of FIG. 3). As aresult, the switch 24 is turned on, the output signal V1 of theoperational amplifier 22 is set to 0 V, and the integrated value isreset ((C) of FIG. 3).

Next, at a timing t4, the control section 27 changes the voltage of thecontrol signal SSW from high level to low level ((B) of FIG. 3). As aresult, the switch 24 is turned off, and the operational amplifier 22and the capacitor 23 are allowed to perform integration operation.

Next, at a timing t5, the drive section 13 performs transition of thevoltage of the drive signal DRV from high level to low level ((A) ofFIG. 3). In response thereto, similarly to at the timing t1 andsubsequent timings, the operational amplifier 22 and the capacitor 23integrate the detection signals SDET, the signal V1 becomes a voltagecorresponding to the proximity state of the external proximity object.At a timing t6, the S/H circuit 25 samples the signal V1, and the ADC 26converts the output signal of the S/H circuit 25 into a digital code((C) of FIG. 3). Then, during a period from a timing t7 to a timing t8,the integrated value is reset ((C) of FIG. 3).

In this way, the analog signal processing section 20 generates thedigital codes based on the detection signals SDET by the respectivetouch sensors of the touch detection device 10. In addition, the analogsignal processing section 20 outputs the digital codes as the map dataMAP1 that is formed of the digital codes of all of the touch sensors onthe touch detection surface.

The digital signal processing section 30 obtains the number of touchevents, touched positions, change at each touch position, and the like,based on the map data MAP1 supplied from the analog signal processingsection 20. The digital signal processing section 30 includes a touchcomponent extraction section 31, a touch position detection section 40,and a tracking processing section 33.

The touch component extraction section 31 generates map data MAP2 for acomponent (a touch component TC) based on the external proximity object,based on the map data MAP1. The touch component extraction section 13has a memory 36. The memory 36 holds map data MAP0 in the case where theexternal proximity object is not present. With this configuration,first, the touch component extraction section 31 previously stores, asthe map data MAP0 in the memory 36, data that is determined that theexternal proximity object is not present, out of the map data MAP1supplied from the analog signal processing section 20. Then, the touchcomponent extraction section 31 obtains a difference between therespective digital codes of the map data MAP1 supplied from the analogsignal processing section 20 and the respective digital codes in the mapdata MAP0 stored in the memory 36. Further, based on the difference, thetouch component extraction section 31 calculates the touch component TCthat becomes a small value close to 0 (zero) when the external proximityobject is not present and becomes a larger value with the externalproximity object approaching, and generates map data MAP2.

The touch position detection section 40 detects the number of touchevents, the touched positions, and the like, based on the map data MAP2.

FIG. 4 illustrates a configuration example of the touch positiondetection section 40. The touch position detection section 40 includes athreshold setting section 41, a binarizing section 42, four labelingprocessing sections 43A to 43D, a touch region arithmetic section 44,and a touch coordinate calculation section 45.

The threshold setting section 41 obtains four thresholds THA to THDbased on the map data MAP2, and supplies the four thresholds THA to THDto the binarizing section 42. Specifically, as will be described later,the threshold setting section 41 detects a peak value of the touchcomponent TC included in the map data MAP2, and divides the peak valueinto four values to obtain four thresholds THA to THD.

The binarizing section 42 compares, based on the map data MAP2, thetouch component TC included in the map data MAP2 with the fourthresholds THA to THD that are supplied from the threshold settingsection 41 to perform binarizing processing, and removes Gaussian noise.Then, the binarizing section 42 outputs the results of the binarizingprocessing as map data MAPA to MAPD.

FIG. 5 illustrates operation of the threshold setting section 41 and thebinarizing section 42, where (A) illustrates touch operation by a user,(B) illustrates the touch component TC, and (C) to (F) illustrate mapdata MAPA to MAPD, respectively.

In this example, as illustrated in (A) of FIG. 5, three fingers of theuser are in contact with or in proximity to a touch detection surface S.As illustrated in (B) of FIG. 5, the touch component TC shows a highvalue at coordinates where the fingers are in contact with or inproximity to the touch detection surface S. The threshold settingsection 41 detects a peak value of the touch component Tc, and sets thepeak value as the threshold THA. Then, the threshold setting section 41sets a value that is three-quarters of the threshold THA as thethreshold THB, sets a value that is half of the threshold THA as thethreshold THC, and sets a value that is a quarter of the threshold THAas the threshold THD.

The binarizing section 42 generates the map data MAPA based on the mapdata MAP2 and the threshold THA ((C) of FIG. 5). Specifically, thebinarizing section 42 sets a value to 1 when the touch component TC isequal to or larger than the threshold THA, and sets the value to 0 whenthe touch component TC is smaller than the threshold THA, to generatethe map data MAPA. In other words, a region indicating “1” in the mapdata MAPA (a region where the touch component TC is equal to or largerthan the threshold THA) is a touched region (a touch region TR).Likewise, the binarizing section 42 generates the map data MAPB based onthe map data MAP2 and the threshold THB ((D) of FIG. 5), generates themap data MAPC based on the map data MAP2 and the threshold THC ((E) ofFIG. 5), and generates the map data MAPD based on the map data MAP2 andthe threshold THD ((F) of FIG. 5).

Note that, in the following description, map data corresponding to ahigh threshold is referred to as high-order map data, and map datacorresponding to a low threshold is referred to as low-order map data,as appropriate. Specifically, for example, the map data MAPA is map datahigher order than the map data MAPB, and the map data MAPB is map datalower order than the map data MAPA.

The labeling processing section 43A performs labeling processing basedon the map data MAPA. Specifically, the labeling processing section 43Aprovides different labels from one another to one or a plurality oftouch regions TR (one touch region TR in the example of (C) of FIG. 5)included in the map data MAPA. Then, the labeling processing section 43Asupplies label information LA that indicates relationship between therespective touch regions TR and the respective labels, together with themap data MAPA, to the touch region arithmetic section 44.

Likewise, the labeling processing sections 43B to 43D perform thelabeling processing based on the map data MAPB to MAPD, respectively,and supply the map data MAPB to MAPD and label information LB to LD tothe touch region arithmetic section 44, respectively.

The touch region arithmetic section 44 obtains the touch regions TRnecessary for calculation of touch positions, based on the map data MAPAto MAPD and the label information LA to LD that are respectivelysupplied from the labeling processing sections 43A to 43D, as will bedescribed later. The touch coordinate calculation section 45 obtainstouch coordinates (touch positions) by a so-called centroid processing,based on the arithmetic results by the touch region arithmetic section44, and outputs the touch positions together with the number of touchevents.

The tracking processing section 33 performs tracking processing based onthe information such as the number of touch events and the touchpositions that are detected by the touch position detection section 40,and obtains change of the respective touch positions. Specifically, thetracking processing section 33 performs so-called vicinity processing toassociate, for example, the respective touch positions obtained bylatest scanning with the respective touch positions obtained by lastscanning. Accordingly, the tracking processing section 33 obtains changeat the respective touch positions. Then, the tracking processing section33 outputs, as touch information IT, the information about the number oftouch events and the touch positions and the information about change atthe respective touch positions.

FIG. 6 illustrates a mounting example of the touch panel 1. In thisexample, the analog signal processing section 20 is mounted as acontroller section 28 on a flexible printed board 29, and the digitalsignal processing section 30 is mounted as a host section 38 on a board39. Note that the configuration is not limited thereto, and for example,a part or all of the digital signal processing section 30 may be mountedas the controller section 28 together with the analog signal processingsection 20.

In this example, the map data MAPA to MAPD correspond to a specificexample of “a plurality of pieces of map data” in the presentdisclosure. The binarizing section 42 corresponds to a specific exampleof “map generation section” in the present disclosure. The labelingprocessing sections 43A to 43D and the touch region arithmetic section44 correspond to a specific example of “labeling section” in the presentdisclosure. The touch coordinate calculation section 45 corresponds to aspecific example of “detection section” in the present disclosure.

(Operation and Function)

Subsequently, operation and a function of the touch panel 1 according tothe first embodiment will be described.

(Entire Operation Outline)

First, entire operation outline of the touch panel 1 is described withreference to FIG. 1, FIG. 4, and the like. The drive section 13sequentially applies the drive signal DRV to the plurality of driveelectrodes 11, based on the control signal (the digital signal) suppliedfrom the control section 27. The drive signal DRV is transmitted to thesensor electrodes 12 through the electrostatic capacitances between thedrive electrodes 11 and the sensor electrodes 12, and is output as thedetection signals SDET from the touch detection device 10. The analogsignal processing section 20 generates the map data MAP1 that indicatesdetection results by all of the touch sensors on the touch detectionsurface of the touch detection device 10, based on the detection signalsSDET supplied from the plurality of sensor electrodes 12 of the touchdetection device 10.

The touch component extraction section 31 generates the map data MAP2for the component (the touch component TC) based on the externalproximity object, based on the map data MAP1. The threshold settingsection 41 of the touch position detection section 40 obtains the fourthresholds THA to THD based on the map data MAP2. The binarizing section42 performs the binarizing processing based on the map data MAP2 and thefour thresholds THA to THD to generate the map data MAPA to MAPD. Thelabeling processing sections 43A to 43D perform the labeling processingbased on the map data MAPA to MAPD to generate the label information LAto LD, respectively. The touch region arithmetic section 44 obtains thetouch regions TR necessary for the calculation of the touch positions,based on the map data MAPA to MAPD and the label information LA to LDthat are respectively supplied from the labeling processing sections 43Ato 43D. The touch coordinate calculation section 45 obtains the touchcoordinates (the touch positions) based on the arithmetic results by thetouch region arithmetic section 44, and outputs the touch positionstogether with the number of touch events. The tracking processingsection 33 performs the tracking processing based on the informationsuch as the number of touch events and the touch positions that aredetected by the touch position detection section 40, to obtain change atthe respective touch positions.

(Detailed Operation of Touch Position Detection Section 40)

The touch position detection section 40 detects the number of touchevents, the touch positions, and the like, based on the map data MAP2.The detailed operation of the touch position detection section 40 isdescribed below by taking the case of the multi-touch illustrated inFIG. 5 as an example.

As illustrated in (A) and (B) of FIG. 5, the threshold value settingsection 41 detects the peak value of the touch component TC, andgenerates the thresholds THA to THD based on the peak value. Thebinarizing section 42 generates the map data MAPA to MAPD based on themap data MAP2 and the thresholds THA to THD. Then, the labelingprocessing sections 43A to 43D perform the labeling processing based onthe map data MAPA to MAPD, respectively.

FIG. 7A to FIG. 7D illustrates the labeling processing by the labelingprocessing sections 43A to 43D, respectively. In this example, asillustrated in FIG. 7A, since one touch region TR is included in the mapdata MAPA, the labeling processing section 43A provides a label L0 tothe touch region TR. In addition, as illustrated in FIG. 7B, since twotouch regions TR are included in the map data MAPB, the labelingprocessing section 43B provides labels L1 and L2 to the respective touchregions TR. Moreover, as illustrated in FIG. 7C, since two touch regionsTR are included in the map data MAPC, the labeling processing section43C provides labels L3 and L4 to the respective touch regions TR.Furthermore, as illustrated in FIG. 7D, since one touch region TR isincluded in the map data MAPD, the labeling processing section 43Dprovides a label L5 to the touch region TR. In this way, the labelingprocessing sections 43A to 43D provide the labels to the respectivetouch region TR included in the respective map data, and generate thelabel information LA to LD, respectively.

FIG. 8 illustrates inclusive relationship of the touch regions TR in themap data MAPA to MAPD. The two touch regions TR provided with the labelsL3 and L4 in the map data MAPC are included in the touch region TRprovided with the label L5 in the map data MAPD. The two touch regionsTR provided with the labels L1 and L2 in the map data MAPB are includedin the touch region TR provided with the label L3 in the map data MAPC.Further, the touch region TR provided with the label L0 in the map dataMAPA is included in the touch region TR provided with the label L1 inthe map data MAPB.

The labeling processing sections 43A to 43D supplies the map data MAPAto MAPD and the label information LA to LD to the touch regionarithmetic section 44, respectively. Then, the touch region arithmeticsection 44 obtains the touch regions TR necessary for calculation of thetouch positions based on the information.

FIG. 9 illustrates a flowchart of operation of the touch regionarithmetic section 44. The touch region arithmetic section 44 performsthe following flow every time the four pieces of map data MAPA to MAPDand the label information LA to LD are supplied from the labelingprocessing sections 43A to 43D, respectively.

First, the touch region arithmetic section 44 sequentially selects thetwo pieces of map data corresponding to the adjacent thresholds out ofthe map data MAPA to MAPD, and performs label association based on theinclusive relationship of the touch regions TR between the selected twopieces of map data (step S1). Specifically, the touch region arithmeticsection 44 performs the label association based on the inclusiverelationship between the touch region TR of the map data MAPD and thetouch regions TR of the map data MAPC, performs the label associationbased on the inclusive relationship between the touch region TR of themap data MAPC and the touch regions TR of the map data MAPB, andperforms the label association based on the inclusive relationshipbetween the touch region TR of the map data MAPB and the touch region TRof the map data MAPA.

FIG. 10 illustrates the label association. As illustrated in FIG. 10,the touch region arithmetic section 44 associates the label L5 of thetouch region TR in the (low-order) map data MAPD with the labels L3 andL4 of the touch regions TR in the (high-order) map data MAPC. In otherwords, as illustrated in FIG. 8, since the two touch regions TR providedwith the labels L3 and L4 are included in the touch region TR providedwith the label L5, the touch region arithmetic section 44 associates thelabel L5 with the two labels L3 and L4 with one to two correspondence.In addition, the touch region arithmetic section 44 associates the labelL3 of the touch region TR in the (low-order) map data MAPC with thelabels L1 and L2 of the touch regions TR in the (high-order) map dataMAPB. In other words, as illustrated in FIG. 8, since the two touchregions TR provided with the labels L1 and L2 are included in the touchregion TR provided with the label L3, the touch region arithmeticsection 44 associates the label L3 with the two labels L1 and L2 withone to two correspondence. Further, the touch region arithmetic section44 associates the label L1 of the touch region TR in the (low-order) mapdata MAPB with the label L0 of the touch region TR in the (high-order)map data MAPA. In other words, as illustrated in FIG. 8, since the touchregion TR provided with the label L0 is included in the touch region TRprovided with the label L1, the touch region arithmetic section 44associates the label L1 with the label L0 with one to onecorrespondence.

Next, as for the labels associated with one to one correspondence, thetouch region arithmetic section 44 replaces the label of the touchregion TR in the high-order map data with the label same as that of thetouch region TR in the low-order map data, and as for the labelsassociated with one to plural correspondence, the touch regionarithmetic section 44 replaces one of the labels of the touch regions TRin the high-order map data with the label same as that of the touchregion TR in the low-order map data, to merge labels (step S2).

FIG. 11 illustrates replacement of the labels. FIG. 12 illustrates themap data MAPA to MAPD and the label information LA and LB after thelabel replacement. At step S1, as illustrated in FIG. 10, the touchregion arithmetic section 44 associates the label L5 of the touch regionTR in the (low-order) map data MAPD with the two labels L3 and L4 of thetouch regions TR in the (high-order) map data MAPC with one to twocorrespondence. Therefore, the touch region arithmetic section 44replaces one (in this example, the label L4) of the two labels L3 and L4of the touch regions TR in the high-order map data MAPC with the labelL5 (FIG. 11). In addition, at the step S1, as illustrated in FIG. 10,the touch region arithmetic section 44 associates the label L3 of thetouch region TR in the (low-order) map data MAPC with the two labels L1and L2 of the touch regions TR in the (high-order) map data MAPB withone to two correspondence. Therefore, the touch region arithmeticsection 44 replaces one (in this example, the label L2) of the twolabels L1 and L2 of the touch regions TR in the high-order map data MAPBwith the label L3 (FIG. 11). Moreover, at the step S1, as illustrated inFIG. 10, the touch region arithmetic section 44 associates the label L1of the touch region TR in the (low-order) map data MAPB with the labelL0 of the touch region TR in the (high-order) map data MAPA with one toone correspondence. Therefore, the touch region arithmetic section 44replaces the label L0 of the touch region TR in the high-order map dataMAPA with the label L1 (FIG. 11). By performing the label replacement inthis way, as illustrated in FIG. 12, the touch region TR provided withthe label L1 is included in each of the two pieces of map data MAPA andMAPB, and the touch region TR provided with the label L3 is included ineach of the two pieces of map data MAPB and MAPC, and the touch regionTR provided with the label L5 is included in each of the two pieces ofmap data MAPC and MAPD.

Then, as for the labels associated with one to plural correspondence,the touch region arithmetic section 44 removes the label of the touchregion TR in the low-order map data (step S3).

FIG. 13 illustrates the map data MAPA to MAPD and the label informationLA and LB after the step S3. As illustrated in FIG. 11, at the step S2,the touch region arithmetic section 44 has associated the label L5 ofthe touch region TR in the (low-order) map data MAPD with the two labelsL3 and L5 of the touch regions TR in the (high-order) map data MAPC withone to two correspondence. Therefore, the touch region arithmeticsection 44 removes the label L5 of the touch region TR in the low-ordermap data MAPD. In addition, as illustrated in FIG. 11, at the step S2,the touch region arithmetic section 44 has associated the label L3 ofthe touch region TR in the (low-order) map data MAPC with the two labelsL1 and L3 of the touch regions TR in the (high-order) map data MAPB withone to two correspondence. Therefore, the touch region arithmeticsection 44 removes the label L3 of the touch region TR in the low-ordermap data MAPC. As a result, as illustrated in FIG. 13, the touch regionTR provided with the label L3 in the map data MAPC and the touch regionTR provided with the label L5 in the map data MAPD disappear, and threetouch regions TR that are respectively provided with the labels L1, L3,and L5 and are separated from one another appear.

The touch region arithmetic section 44 obtains the touch regionsnecessary for calculation of the touch coordinates through theabove-described flow.

The touch coordinate calculation section 45 obtains touch coordinates(touch positions) by so-called centroid processing, based on the touchregions TR obtained by the touch region arithmetic section 44.

FIG. 14 illustrates operation of the touch coordinate calculationsection 45. The touch coordinate calculation section 45 performs thecentroid processing on the touch regions TR obtained by the touch regionarithmetic section 44 to obtain a centroid coordinate CP of each of thetouch regions TR. Then, the touch coordinate calculation section 45outputs each centroid coordinate CP as the touch position as well asoutputs the number of the touch regions TR (in this example, three) asthe number of touch events.

In this way, in the touch panel 1, the threshold setting section 41obtains the four thresholds THA to THD, based on the peak value of thetouch component TC included in the map data MAP2, and the binarizingsection 42 performs the binarizing processing with use of the thresholdsTHA to THD to generate the map data MAPA to MAPD. Further, the labelingprocessing sections 43A to 43D perform the labeling processing on themap data MAPA to MAPD, respectively, and the touch region arithmeticsection 44 performs the label replacement based on the inclusiverelationship of the touch regions TR. Accordingly, as will be describedin comparison with a comparative example below, in the touch panel 1, itis possible to obtain the touch positions and the number of touch eventsmore accurately even in the case of multi-touch.

Moreover, in the touch panel 1, the labeling processing sections 43A to43D perform the labeling processing on the binarized map data MAPA toMAPD, respectively. Therefore, it is possible to reduce memory capacity.In other words, for example, when each labeling processing sectionperforms the labeling processing based on the map data MAP2 for thecomponent (the touch component TC) based on the external proximityobject, it is necessary for each labeling processing section to have amemory that holds the map data MAP2, namely, a memory that holds thetouch component TC relating to all of the touch sensors on the touchdetection surface. On the other hand, in the touch panel 1 according tothe first embodiment, the labeling processing sections 43A to 43Dperform the labeling processing on the binarized map data MAPA to MAPD,respectively. Therefore, since data amount to be handled is small, it ispossible to reduce memory capacity.

Moreover, in the touch panel 1, the threshold setting section 41 obtainsthe four thresholds THA to THD based on the peak value of the touchcomponent TC included in the map data MAP2. Therefore, it is possible toobtain the touch positions and the number of touch events moreaccurately. In other words, for example, in the case where a finger of auser is not in contact with the touch detection surface S and is inproximity to the touch detection surface S, the touch component TC issmaller than that in the case where the finger of the user is in contactwith the touch detection surface S. Also in this case, the thresholdsetting section 41 obtains the four thresholds THA to THD based on thepeak value of the touch component TC. Therefore, the touch regions TRare generated in each of the four pieces of the map data MAPA to MAPD.In other words, for example, when the four thresholds THA to THD arefixed, the touch region TR may possibly not be generated in one or moreof the four pieces of the map data MAPA to MAPD. In the touch panel 1according to the first embodiment, however, since the thresholds THA toTHD are obtained based on the touch component TC, the touch regions TRare generated in each of the map data MAPA to MAPD. Accordingly, in thetouch panel 1, it is possible to obtain the touch positions and thenumber of touch events more accurately.

Comparative Example

Next, a touch panel 1R according to a comparative example is described.In the comparative example, a digital processing section 30R thatperforms binarizing processing with use of a predetermined threshold anddoes not perform label replacement is used. Other configurations aresimilar to those in the first embodiment (FIG. 1 and the like).

FIG. 15 illustrates operation of a binarizing section 42R of the digitalprocessing section 30R, where (A) illustrates the touch component TC,(B) illustrates map data in the case where the threshold is set to ahigh value, and (C) illustrates map data in the case where the thresholdis set to a low value. Similar to FIG. 5, FIG. 15 illustrates operationwhen multi-touch is performed by three fingers of a user. In thisexample, as illustrated in (B) and (C) of FIG. 15, only two touchregions TR appear in the map data even when the threshold value is setto whatever value. In other words, in this example, the digitalprocessing section 30R is not allowed to obtain three touch regions TReven though the user touches the touch panel with three fingers. In thisway, in the touch panel 1R, the touch positions and the number of touchevents may not be obtained accurately in the case of multi-touch.

On the other hand, in the touch panel 1 according to the firstembodiment, after the four pieces of map data MAPA to MAPD are generatedbased on the four thresholds THA to THD and the labeling processing areperformed on the four pieces of map data MAPA to MAPD, the labelreplacement is performed based on the inclusive relationship of thetouch regions TR. Accordingly, in this example, the label replacement isperformed based on the map data MAPA to MAPD (FIG. 7A to FIG. 7D) inwhich only two or less touch regions TR appear, which makes it possibleto generate three touch regions TR as illustrated in FIG. 13. As aresult, it is possible to obtain the touch positions and the number oftouch events more accurately.

(Effects)

As described above, in the first embodiment, after the plurality ofpieces of map data is generated based on the plurality of thresholds andthe labeling processing is performed on the plurality of pieces of mapdata, the label replacement is performed based on the inclusiverelationship of the touch regions. Therefore, in the case ofmulti-touch, it is possible to obtain the touch positions and the numberof touch events more accurately.

In addition, in the first embodiment, the plurality of thresholds isobtained based on the peak value of the touch component. Therefore, itis possible to obtain the touch positions and the number of touch eventsmore accurately even when the external proximity object is not incontact with the touch detection surface.

Moreover, in the first embodiment, each of the labeling sectionsperforms the labeling processing on the binarized map data. Therefore,it is possible to reduce memory capacity.

(Modification 1-1)

In the above-described first embodiment, the threshold setting sections41 generates the four thresholds THA to THD, and the four labelingprocessing sections 43A to 43D perform the labeling processing on thefour pieces of map data MAPA to MAPD that are generated with use of thethresholds THA to THD, respectively. However, the configuration is notlimited thereto, and alternatively, for example, the threshold settingsection 41 may generate two, three, or five or more thresholds, andlabeling processing sections of the same number (namely, two, three, orfive or more) as the number of the thresholds may perform the labelingprocessing on the map data generated with use of the thresholds.

(Modification 1-2)

In the above-described first embodiment, the four labeling processingsections 43A to 43D are provided and the labeling processing on the mapdata MAPA to MAPD is performed by parallel processing. However, this isnot limitative, and for example, one labeling processing section may beprovided and the labeling processing may be time-divisionally performedon the map data MAPA to MAPD.

2. Second Embodiment

Next, a touch panel 2 according to a second embodiment is described. Thetouch panel 2 is configured using a touch region arithmetic section 54that obtains the touch regions TR necessary for calculation of the touchpositions by a method different from the method of the touch regionarithmetic section 44. Other configurations of the touch panel 2 aresimilar to those in the above-described first embodiment (FIG. 1, FIG.4, and the like). Note that like numerals are used to designatesubstantially like components of the touch panel 1 according to theabove-described first embodiment, and the description thereof isappropriately omitted.

FIG. 16 illustrates a flowchart of operation of the touch regionarithmetic section 54. The touch region arithmetic section 54 performsthe following flow every time the four pieces of map data MAPA to MAPDand the label information LA to LD are supplied from the labelingprocessing sections 43A to 43D, respectively.

First, the touch region arithmetic section 54 selects the touch regionTR provided with the label L0 as a focus region R (step S11). In otherwords, the touch region arithmetic section 54 focuses on the touchregion TR provided with the label L0 in the highest-order map data MAPA.

Next, the touch region arithmetic section 54 confirms whether the focusregion R includes the touch region TR with a replaced label in the mapdata higher order by one than the map data including the focus region R(step S12). When the focus region R does not include such a touch regionTR, the label of the focus region R is replaced with an unused minimumlabel (step S13), and the process proceeds to step S17. Moreover, whenthe focus region R includes such a touch region TR, the process proceedsto step S14.

At the step S12, when the focus region R includes such a touch regionTR, the touch region arithmetic section 54 confirms whether the focusregion R includes a plurality of such touch regions TR (step S14). Whenthe focus region R does not include the plurality of such touch regionsTR, it means that the focus region R includes only one touch region TR.Therefore, the label of the focus region R is replaced with the labelsame as that of the one touch region TR (step S15), and the processproceeds to the step S17. Moreover, when the focus region R includes theplurality of such touch regions TR, the process proceeds to step S16.

At the step S14, when the focus region R includes the plurality of suchtouch regions TR, the touch region arithmetic section 54 replaces thelabel of the focus region R with a predetermined label LX (step S16). Atthis time, as the predetermined label LX, for example, a label of alarge number that is not used in the labeling processing and the labelreplacement may be used.

Next, the touch region arithmetic section 54 confirms whether all of thetouch regions TR in the map data MAPA to MAPD are selected as the focusregion R (step S17). When all of the touch regions TR are not selectedas the focus region R, the touch region arithmetic section 54 selects,as the focus region R, the touch region TR provided with a labelsubsequent to the label of the focus region R (step S18), and theprocess proceeds to the step S12.

At the step S17, when all of the touch regions TR are selected as thefocus region R, the touch region arithmetic section 54 removes the labelLX from all of the touch regions TR provided with the label LX (stepS19).

The flow is ended in this way.

Next, operation of the touch region arithmetic section 54 will bedescribed with the map data MAPA to MAPD and the label information LA toLD illustrated in FIGS. 7A to 7D as an example.

FIG. 17A to FIG. 17E illustrate an operation example of the touch regionarithmetic section 54.

First, the touch region arithmetic section 54 selects the touch regionTR (FIG. 7A) provided with the label L0 as the focus region R (stepS11). The focus region R is included in the highest-order map data MAPAand map data higher order than the map data MAPA is not present.Therefore the focus region R does not include the touch region TR with areplaced label in the higher-order map data (step S12). Therefore, thetouch region arithmetic section 54 replaces the label L0 of the focusregion R with a label L6 that is an unused minimum label (step S13).Specifically, as illustrated in FIGS. 7A to 7D, in this example, thelabeling processing sections 43A to 43D provides the labels L0 to L5 tothe touch regions TR in the map data MAPA to MAPD, respectively.Therefore, the unused minimum label is the label L6. Accordingly, thetouch region arithmetic section 54 replaces the label L0 of the focusregion R with the label L6. As a result, the label of the touch regionTR in the map data MAPA is as illustrated in FIG. 17A. Incidentally, inthis example, the label of the focus region R is replaced with theunused minimum label. However, this is not limitative, andalternatively, for example, the label of the focus region R may bereplaced with a label that is not unused and so-called carry.

Next, the touch region arithmetic section 54 selects the touch region TRprovided with the label L1 (FIG. 7B) as the focus region R (step S18).The focus region R includes one touch region TR whose label is replacedfrom the label L0 to the label L6 in the map data MAPA (FIG. 7A and FIG.17A) higher order by one than the map data MAPB including the focusregion R (steps S12 and S14). Accordingly, the touch region arithmeticsection 54 replaces the label L1 of the focus region R with the label L6(step S15).

Next, the touch region arithmetic section 54 selects the touch region TRprovided with the label L2 (FIG. 7B) as the focus region R (step S18).The focus region R does not include the touch region TR with a replacedlabel in the map data MAPA (FIG. 7A and FIG. 17A) higher order by onethan the map data MAPB including the focus region R (step S12).Therefore, the touch region arithmetic section 54 replaces the label L2of the focus region R with a label L7 that is an unused minimum label(step S13). As a result, the labels of the touch regions TR in the mapdata MAPA and MAPB are as illustrated in FIG. 17B.

Next, the touch region arithmetic section 54 selects the touch region TRprovided with the label L3 (FIG. 7C) as the focus region R (step S18).The focus region R includes the touch region TR whose label is replacedfrom the label L1 to the label L6 and the touch region TR whose label isreplaced from the label L2 to the label L7 in the map data MAPB (FIG. 7Band FIG. 17B) higher order by one than the map data MAPC including thefocus region R (steps S12 and S14). In other words, the focus region Rincludes the two touch regions TR in the next higher-order map dataMAPB. Accordingly, the touch region arithmetic section 54 replaces thelabel L3 of the focus region R with the predetermined label LX (stepS16).

Next, the touch region arithmetic section 54 selects the touch region TRprovided with the label L4 (FIG. 7C) as the focus region R (step S18).The focus region R does not includes the touch region TR with thereplaced label in the map data MAPB (FIG. 7B and FIG. 17B) higher orderby one than the map data MAPC including the focus region R (step S12).Therefore, the touch region arithmetic section 54 replaces the label L4of the focus region R with an unused minimum label L8 (step S13). As aresult, the labels of the touch regions TR in the map data MAPA to MAPCare as illustrated in FIG. 17C.

Next, the touch region arithmetic section 54 selects the touch region TRprovided with the label L5 (FIG. 7D) as the focus region R (step S18).The focus region R includes the touch region TR whose label is replacedfrom the label L3 to the label LX and the touch region TR whose label isreplaced from the label L4 to the label L8 in the map data MAPC (FIG. 7Cand FIG. 17C) higher order by one than the map data MAPD including thefocus region R (steps S12 and S14). In other words, the focus region Rincludes the two touch regions TR in the next higher-order map dataMAPC. Therefore, the touch region arithmetic section 54 replaces thelabel L5 of the focus region R with the predetermined label LX (stepS16). As a result, the labels of the touch regions TR in the map dataMAPA to MAPD are as illustrated in FIG. 17D.

Then, the touch region arithmetic section 54 removes the label LX fromthe all of the touch regions TR provided with the label LX (step S19).As a result, as illustrated in FIG. 17E, three touch region TR that arerespectively provided with the labels L6, L7 and L8 and are separatefrom one another appear.

As described above, in the second embodiment, the label replacement isperformed in order from the touch region provided with the label L0,namely, in order from the touch region included in the higher-order mapdata, based on the inclusive relationship of the touch regions. Even inthis case, it is possible to obtain effects similar to those in theabove-described first embodiment.

3. Third Embodiment

Next, a touch panel 3 according to a third embodiment is described. Inthe third embodiment, the touch regions TR necessary for calculation oftouch positions are obtained while labeling on the map data MAPA to MAPDis performed. Specifically, in the above-described first embodiment andthe like, after the labeling processing sections 43A to 43D perform thelabeling processing, the touch regions TR necessary for calculation ofthe touch positions are obtained through the label replacement. In thethird embodiment, however, the touch regions TR necessary forcalculation of the touch positions are obtained while labelingprocessing is sequentially performed. Note that like numerals are usedto designate substantially like components of the touch panel 1according to the above-described first embodiment, and the descriptionthereof is appropriately omitted.

As illustrated in FIG. 1, the touch panel 3 includes a digital signalprocessing section 60. The digital signal processing section 60 includesa touch position detection section 70.

FIG. 18 illustrates a configuration example of the touch positiondetection section 70. The touch position detection section 70 includes amultiplexer 72 and a labeling processing section 73. The multiplexer 72selects and outputs one of the input map data MAPA to MAPD in order fromthe lower-order map data, namely, in order of the map data MAPD, MAPC,MAPB, and MAPA. The labeling processing section 73 performs the labelingprocessing in order from the lower-order map data based on the map dataMAPA to MAPD that are sequentially supplied from the multiplexer 72, andobtains the touch regions TR necessary for calculation of the touchpositions.

FIG. 19 illustrates a flowchart of operation of the labeling processingsection 73.

First, the labeling processing section 73 selects the lowest-order mapdata MAPD as a labeling target map data RL1 as well as sets the entiremap data MAPD as a labeling target region RL2, and performs the labelingprocessing on the labeling target region RL2 of the labeling target mapdata RL1 (step S21).

Then, the labeling processing section 73 sets the touch region TR thatis provided with a label by the labeling processing on the labelingtarget map data RL1, as new labeling target region RL2 as well asselects map data higher order by one than the labeling target map dataRL1, as new labeling target map data RL1, and performs the labelingprocessing on the labeling target region RL2 of the labeling target mapdata RL1 (step S22).

Next, the labeling processing section 73 provides and replaces thelabels in the labeling processing at the step S22 (step S23).

FIG. 20 illustrates a flowchart of operation of providing and replacingthe labels.

First, the labeling processing section 73 selects one of the touchregions TR in the map data lower order by one than the labeling targetmap data RL1, as the focus region R (step S31).

Next, the labeling processing section 73 confirms whether the focusregion R includes the touch region TR of the labeling target map dataRL1 (step S32). When it is confirmed that the focus region R does notinclude such a touch region TR, the process proceeds to step S37.

At the step S32, when it is confirmed that the focus region R includesthe touch region TR of the labeling target map data RL1, the labelingprocessing section 73 confirms whether the focus region R includes aplurality of the touch regions TR of the labeling target map data RL1(step S33). When it is confirmed that the focus region R does notinclude the plurality of touch regions TR of the labeling target mapdata RL1, it means that the focus region R includes only one touchregion TR. Therefore, the labeling processing section 73 provides theone touch region TR with the same label as that of the focus region R(step S34), and the process proceeds to the step S37.

At the step S33, when it is confirmed that the focus region R includesthe plurality of touch regions TR of the labeling target map data RL1,the labeling processing section 73 provides one of the plurality oftouch regions TR with the same label as that of the focus region R andprovides the other touch regions TR with an unused minimum label (stepS35).

Next, the labeling processing section 73 replaces the label of the focusregion R with the predetermined label LX (step S36).

Next, the labeling processing section 73 confirms whether all of thetouch regions TR in the map data lower order by one than the labelingtarget map data RL1 are selected as the focus region R (step S37). Whenit is confirmed that all of the touch regions TR are not selected as thefocus region R, the labeling processing section 73 selects the touchregion TR that is not yet selected, as the focus region R (step S38),and the process proceeds to the step S32.

At the step S37, when it is confirmed that all of the touch regions TRare selected as the focus region R, the labeling processing section 73proceeds to step S24 (FIG. 19).

Next, the labeling processing section 73 confirms whether all of the mapdata MAPA to MAPD are selected as the labeling target map data RL1 (stepS24). When it is confirmed that all of the map data MAPA to MAPD are notselected as the labeling target map data RL1, the process proceeds tothe step S22.

At the step S24, when it is confirmed that all of the map data MAPA toMAPD are selected as the labeling target map data RL1, the labelingprocessing section 73 removes the label LX from all of the touch regionsTR provided with the label LX (step S25).

The flow is ended in this way.

Next, operation of the labeling processing section 73 is described withthe map data MAPA to MAPD illustrated in (C) to (F) of FIG. 5 as anexample.

FIGS. 21A to 21E illustrate an operation example of the labelingprocessing section 73.

First, the labeling processing section 73 selects the map data MAPD ((F)of FIG. 5) as the labeling target map data RL1 as well as sets theentire map data MAPD as the labeling target region RL2 to perform thelabeling processing (step S21). As a result, the label of the touchregion TR in the map data MAPD is as illustrated in FIG. 21A.

Next, the labeling processing section 73 sets the touch region TRprovided with the label L0 as new labeling target region RL2 as well asselects the map data MAPC ((E) of FIG. 5) higher order by one than themap data MAPD as the labeling target map data RL1 to perform thelabeling processing (step S22).

At this time, first, the labeling processing section 73 selects, as thefocus region R, the touch region TR provided with the label L0 in themap data MAPD ((F) of FIG. 5 and FIG. 21A) lower order by one than thelabeling target map data RL1 (MAPC) (step S31). Since the focus region Rincludes two touch regions TR in the map data MAPC ((E) of FIG. 5)(steps S32 and S33), the labeling processing section 73 provides one ofthe two touch regions TR with the same label as the label L0 of thefocus region R, and provides the other touch region TR with an unusedminimum label L1 (step S35). Then, the labeling processing section 73replaces the label of the focus region R from the label L0 to thepredetermined label LX (step S36). After that, since only one touchregion TR is included in the map data MAPD, the labeling processingsection 73 determines that all of the touch regions TR are selected asthe focus region R (step S37). As a result, the labels of the respectivetouch regions TR in the map data MAPC and MAPD are as illustrated inFIG. 21B.

Next, the labeling processing section 73 sets the two touch regions TRprovided with the labels L0 and L1 in the map data MAPC, as new labelingtarget region RL2 as well as selects the map data MAPB ((D) of FIG. 5)higher order by one than the map data MAPC, as the labeling target mapdata RL1 to perform the labeling processing (step S22).

At this time, first, the labeling processing section 73 selects thetouch region TR provided with the label L0 in the map data MAPC ((E) ofFIG. 5 and FIG. 21B) lower order by one than the labeling target mapdata RL1 (MAPB), as the focus region R (step S31). Since the focusregion R does not include the touch region TR in the map data MAPB ((D)of FIG. 5), the labeling processing section 73 then selects the touchregion TR provided with the label L1 in the map data MAPC ((E) of FIG. 5and FIG. 21B), as the focus region R (steps S37 and S38). Since thefocus region R includes the two touch regions TR in the map data MAPB((D) of FIG. 5) (steps S32 and S33), the labeling processing section 73provides one of the two touch regions TR with the label same as thelabel L1 of the focus region R, and provides the other touch region TRwith an unused minimum label L2 (step S35). In addition, the labelingprocessing section 73 replaces the label of the focus region R from thelabel L1 to the predetermined label LX (step S36). As a result, thelabels of the respective touch regions TR in the map data MAPB to MAPDare as illustrated in FIG. 21C.

Next, the labeling processing section 73 sets the touch regions TRprovided with the labels L1 and L2 in the map data MAPB as new labelingtarget region RL2 as well as selects the map data MAPA ((C) of FIG. 5)higher order by one than the map data MAPB as the labeling target mapdata RL1 to perform the labeling processing (step S22).

At this time, first, the labeling processing section 73 selects thetouch region TR provided with the label L1 in the map data MAPB ((D) ofFIG. 5 and FIG. 21C) lower order by one than the labeling target mapdata RL1 (MAPA), as the focus region R (step S31). Since the focusregion R does not include the touch region TR in the map data MAPA ((C)of FIG. 5) (step S32), the labeling processing section 73 then selectsthe touch region TR provided with the label L2 in the map data MAPB ((D)of FIG. 5 and FIG. 21C), as the focus region R (steps S37 and S38).Since the focus region R includes one touch region TR in the map dataMAPA ((C) of FIG. 5) (steps S32 and S33), the labeling processingsection 73 provides the touch region TR with the label same as the labelL2 of the focus region R (step S34). As a result, the labels of therespective touch regions TR in the map data MAPA to MAPD are asillustrated in FIG. 21D.

Then, the labeling processing section 73 removes the label LX from allof the touch regions TR provided with the label LX (step S25). As aresult, as illustrated in FIG. 21E, three touch regions TR that areprovided with the labels L0, L1, and L2 and are separated from oneanother appear.

As described above, in the third embodiment, the labeling processing isperformed in order from lower-order map data while the labeling targetregion is narrowed based on the inclusive relationship of the touchregions. Accordingly, it is possible to obtain effects similar to thosein the above-described first embodiment and the like.

4. Application Examples

Next, application examples of the touch panel described in theabove-described embodiments and modifications will be described.

FIG. 22 illustrates an appearance of a smartphone to which the touchpanel according to any of the above-described embodiments and the likeis applied. For example, the smartphone may include a main body 210, anoperation section 220, and a display section 230. The touch panelaccording to any of the above-described embodiments and the like isapplied to the display section 230.

FIG. 23 illustrates an appearance of a portable game machine to whichthe touch panel according to any of the above-described embodiments andthe like is applied. For example, the portable game machine may includea main body 310, operation sections 321 and 322, and a display section330. The touch panel according to any of the above-described embodimentsand the like is applied to the display section 330.

FIG. 24 illustrates an appearance of a notebook personal computer towhich the touch panel according to any of the above-described embodimentand the like is applied. For example, the notebook personal computerincludes a main body 410, a key board 420, and a display section 430.The touch panel according to any of the above-described embodiments andthe like is applied to the display section 430.

The touch panel according to any of the above-described embodiments andthe like is applicable to electronic apparatuses in all fields, such asa portable music player, a digital camera, and a video camera, inaddition to the smart phone, the portable game player, and the notebookpersonal computer described above. In other words, the touch panelaccording to any of the above-described embodiments and the like isapplicable to electronic apparatuses each displaying an image, in allfields.

Hereinbefore, although the technology has been described with referringto the embodiments, the modifications, and the application examples tothe electronic apparatuses, the technology is not limited thereto, andvarious modifications may be made.

For example, in each of the above-described embodiments, theelectrostatic capacitance type touch detection device 10 is used.However, this is not limitative, and alternatively, for example, a touchdetection device of an optical type or the like maybe used.

In addition, for example, in each of the above-described embodiments,the touch panel is singularly configured. However, this is notlimitative, and alternatively, for example, a display panel and a touchpanel may be integrally configured, and thus the display panel may havea touch detection function. Specifically, for example, a so-calledon-cell type display panel in which a touch detection device is formeddirectly on a display surface of a display panel, or a so-called in-celltype display panel in which a touch detection device is formed in adisplay panel may be used.

Note that the technology may be configured as follows.

(1) A touch detection circuit including:

a map generation section configured to compare a touch signalcorresponding to a proximity state of an external proximity object witheach of a plurality of thresholds to generate a plurality of pieces ofmap data each showing touch regions;

a labeling section configured to selectively perform labeling on thetouch regions in the plurality of pieces of map data, based on inclusiverelationship of the touch regions between the plurality of pieces of mapdata; and

a detection section configured to perform touch detection based onprocessing results by the labeling section.

(2) The touch detection circuit according to (1), further including

a threshold setting section configured to set the plurality ofthresholds based on the touch signal.

(3) The touch detection circuit according to (1) or (2), wherein thedetection section detects the number of touch events and touchpositions.

(4) The touch detection circuit according to any one of (1) to (3),wherein the labeling section generates a first label set indicatingcorrespondence between the touch regions and labels by

providing the labels to the respective touch regions in each of the mapdata, and

sequentially selecting two pieces of map data corresponding to twothresholds adjacent to each other, from the plurality of pieces of mapdata, and replacing the labels based on the inclusive relationship ofthe touch regions in the selected two pieces of map data.

(5) The touch detection circuit according to (4), wherein the labelingsection generates the first label set by,

when one touch region in low-order map data corresponding to a lowthreshold, of the selected two pieces of map data, includes a pluralityof touch regions in high-order map data corresponding to a highthreshold, replacing a label of one of the plurality of touch regions inthe high-order map data with a label same as a label of the one touchregion in the low-order map data, and

when one touch region in the low-order map data of the selected twopieces of map data includes a single touch region in the high-order mapdata, replacing a label of the single touch region with a label same asa label of the one touch region.

(6) The touch detection circuit according to (4) or (5), wherein thelabeling section generates a second label set by, after generating thefirst label set, sequentially selecting two pieces of map datacorresponding to two thresholds adjacent to each other, from theplurality of pieces of map data, and when one touch region in thelow-order map data corresponding to a low threshold, of the selected twopieces of map data, includes a plurality of touch regions in high-ordermap data corresponding to a high threshold, removing a label of the onetouch region in the first label set.(7) The touch detection circuit according to (4), wherein the labelingsection selects the two pieces of map data in order from map datacorresponding to a high threshold.(8) The touch detection circuit according to (7), wherein the labelingsection generates the first label set by,

when one touch region in low-order map data corresponding to a lowthreshold, of the selected two pieces of map data, includes a pluralityof touch regions in high-order map data corresponding to a highthreshold, replacing a label of the one touch region with a dummy label,and

when one touch region in the low-order map data of the selected twopieces of map data includes a single touch region in the high-order mapdata, replacing the label of the one touch region with a label same as alabel of the single touch region.

(9) The touch detection circuit according to (8), wherein the labelingsection generates a second label set by, after generating the firstlabel set, removing the dummy label from the first label set.

(10) The touch detection circuit according to any one of (1) to (3),wherein the labeling section generates a first label set indicatingcorrespondence between the touch regions and labels by sequentiallyselecting two pieces of map data corresponding to two thresholdsadjacent to each other, from the plurality of pieces of map data, andproviding labels to the respective touch regions in each of the mapdata, based on inclusive relationship of the touch regions in theselected two pieces of map data.(11) The touch detection circuit according to (10), wherein the labelingsection selects the two pieces of map data in order from map datacorresponding to a low threshold.(12) The touch detection circuit according to (11), wherein

when one touch region in low-order map data corresponding to the lowthreshold, of the selected two pieces of map data, includes a pluralityof touch regions in high-order map data corresponding to a highthreshold, the labeling section replaces a label of the one touch regionwith a dummy label after providing one of the plurality of touch regionswith a label same as the label of the one touch region, and

when one touch region in the low-order map data of the selected twopieces of map data includes a single touch region in the high-order mapdata, the labeling section provides the single touch region with a labelsame as the label of the one touch region.

(13) The touch detection circuit according to (12), wherein the labelingsection generates a second label set by, after generating the firstlabel set, removing the dummy label from the first label set.

(14) A touch detection method including:

comparing a touch signal corresponding to a proximity state of anexternal proximity object with each of a plurality of thresholds togenerate a plurality of pieces of map data each showing touch regions;

selectively performing labeling on the touch regions in the plurality ofpieces of map data based on inclusive relationship of the touch regionsbetween the plurality of pieces of map data; and

performing touch detection based on labeling results.

(15) An electronic apparatus provided with a touch detection deviceconfigured to detect an external proximity object, and a touch detectioncircuit, the touch detection circuit including:

a map generation section configured to compare a touch signalcorresponding to a proximity state of the external proximity object tothe touch detection device with each of a plurality of thresholds togenerate a plurality of pieces of map data each showing touch regions;

a labeling section configured to selectively perform labeling on thetouch regions in the plurality of pieces of map data, based on inclusiverelationship of the touch regions between the plurality of pieces of mapdata; and

a detection section configured to perform touch detection based onprocessing results by the labeling section.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A touch detection circuitcomprising: a map generation section configured to compare a touchsignal corresponding to a proximity state of an external proximityobject with each of a plurality of thresholds to generate a plurality ofpieces of map data each showing touch regions; a labeling sectionconfigured to selectively perform labeling on the touch regions in theplurality of pieces of map data, based on inclusive relationship of thetouch regions between the plurality of pieces of map data; and adetection section configured to perform touch detection based onprocessing results by the labeling section, wherein the labeling sectionis configured to generate a first label set indicating correspondencebetween the touch regions and labels by providing the labels to therespective touch regions in each of the map data, and sequentiallyselecting two pieces of map data corresponding to two thresholdsadjacent to each other, from the plurality of pieces of map data, andreplacing the labels based on the inclusive relationship of the touchregions in the selected two pieces of map data.
 2. The touch detectioncircuit according to claim 1, further comprising a threshold settingsection configured to set the plurality of thresholds based on the touchsignal.
 3. The touch detection circuit according to claim 1, wherein thedetection section detects the number of touch events and touchpositions.
 4. The touch detection circuit according to claim 1, whereinthe labeling section generates the first label set by, when one touchregion in low-order map data corresponding to a low threshold, of theselected two pieces of map data, includes a plurality of touch regionsin high-order map data corresponding to a high threshold, replacing alabel of one of the plurality of touch regions in the high-order mapdata with a label same as a label of the one touch region in thelow-order map data, and when one touch region in the low-order map dataof the selected two pieces of map data includes a single touch region inthe high-order map data, replacing a label of the single touch regionwith a label same as a label of the one touch region.
 5. The touchdetection circuit according to claim 1, wherein the labeling sectiongenerates a second label set by, after generating the first label set,sequentially selecting two pieces of map data corresponding to twothresholds adjacent to each other, from the plurality of pieces of mapdata, and when one touch region in the low-order map data correspondingto a low threshold, of the selected two pieces of map data, includes aplurality of touch regions in high-order map data corresponding to ahigh threshold, removing a label of the one touch region in the firstlabel set.
 6. The touch detection circuit according to claim 1, whereinthe labeling section selects the two pieces of map data in order frommap data corresponding to a high threshold.
 7. The touch detectioncircuit according to claim 6, wherein the labeling section generates thefirst label set by, when one touch region in low-order map datacorresponding to a low threshold, of the selected two pieces of mapdata, includes a plurality of touch regions in high-order map datacorresponding to a high threshold, replacing a label of the one touchregion with a dummy label, and when one touch region in the low-ordermap data of the selected two pieces of map data includes a single touchregion in the high-order map data, replacing the label of the one touchregion with a label same as a label of the single touch region.
 8. Thetouch detection circuit according to claim 7, wherein the labelingsection generates a second label set by, after generating the firstlabel set, removing the dummy label from the first label set.
 9. Thetouch detection circuit according to claim 1 wherein the labelingsection selects the two pieces of map data in order from map datacorresponding to a low threshold.
 10. The touch detection circuitaccording to claim 9, wherein when one touch region in low-order mapdata corresponding to the low threshold, of the selected two pieces ofmap data, includes a plurality of touch regions in high-order map datacorresponding to a high threshold, the labeling section replaces a labelof the one touch region with a dummy label after providing one of theplurality of touch regions with a label same as the label of the onetouch region, and when one touch region in the low-order map data of theselected two pieces of map data includes a single touch region in thehigh-order map data, the labeling section provides the single touchregion with a label same as the label of the one touch region.
 11. Thetouch detection circuit according to claim 10, wherein the labelingsection generates a second label set by, after generating the firstlabel set, removing the dummy label from the first label set.
 12. Atouch detection method comprising: comparing a touch signalcorresponding to a proximity state of an external proximity object witheach of a plurality of thresholds to generate a plurality of pieces ofmap data each showing touch regions; selectively performing labeling onthe touch regions in the plurality of pieces of map data based oninclusive relationship of the touch regions between the plurality ofpieces of map data by a labeling section; and performing touch detectionbased on labeling results, wherein the labeling section is configured togenerate a first label set indicating correspondence between the touchregions and labels by providing the labels to the respective touchregions in each of the map data, and sequentially selecting two piecesof map data corresponding to two thresholds adjacent to each other, fromthe plurality of pieces of map data, and replacing the labels based onthe inclusive relationship of the touch regions in the selected twopieces of map data.
 13. An electronic apparatus provided with a touchdetection device including the touch detection circuit according toclaim 1.